Ala. Code § 21-1-18

All expenditures of funds of whatever nature for labor, services, or work or for the purchase or lease of materials, equipment, supplies, or other personal property involving $500.00 or more made by or on behalf of the Alabama Institute for Deaf and Blind shall be made under contractual agreement entered into by free and open competitive bidding on sealed bids to the lowest responsible bidder. All such expenditures shall be subject to the provisions of Sections 41-16-50 through 41-16-63, in the same manner and to the same extent as are expenditures by or for state trade schools, state junior colleges, and state colleges and universities under the supervision and control of the State Board of Education; provided, however, that this section shall not apply to purchases of any commodity for which an open public market is maintained, including but not limited to grains and broomcorn, if such commodity is purchased at a price not higher than the prevailing open market price.